I think the 3rd cylinder would do the most good. I had a 1688 with three cylinders and that combine would lift anything. Congrads on the good corn. Where are you atIJ
We had to add the third cylinder to our 03 2388 to lift a 12 row 30" corn hd. Does a good job now. Cost a little over $800, you have to do a little welding. The kit is pictured in the 03 Product upgrade catalog.